Portable chair



FIG. 1 is a top, front, right perspective view of a portable chair showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines immediately adjacent to the shaded area represent unclaimed boundaries of the design. The broken lines showing the remainder of the portable chair represent unclaimed subject matter and form no part of the claimed design. 

CLAIM The ornamental design for a portable chair, as shown and described. 